The present invention relates to a fluid dispenser comprising a reservoir serving to contain fluid and defining an actuating wall which is pressed in order to reduce the volume of the reservoir. The dispenser further comprises a dispensing orifice via which the fluid is dispensed each time the wall of the reservoir is actuated.
Numerous dispensers of that type exist in the prior art. They are used, in particular, for pharmaceuticals, cosmetics, and perfumes. They are also to be found in the form of samples distributed free of charge for advertising purposes, and containing small quantities or xe2x80x9cdosesxe2x80x9d of fluid. The dispenser is then in the form merely of packaging formed of a flexible reservoir provided with a dispensing orifice. The user grasps the packaging between the thumb and the forefinger and presses on the flexible walls of the reservoir to cause the fluid to be dispensed through the dispensing orifice.
Unfortunately, that type of dispenser often does not provide good dispensing quality, in particular good spraying quality, when the fluid is in the form of a liquid, such as a perfume. That is because the spraying is directly dependent on the force with which the user presses the walls of the flexible reservoir. If the user presses slowly, spraying is not good, and the fluid tends to drip out rather than being sprayed out. To mitigate that problem of dispensing quality, the dispenser described in Document FR-2 778 639 recommends imparting a predetermined resistance-to-deformation threshold to the actuating wall, it being necessary to go beyond said threshold in order to deform said wall. That actuating wall does not deform as soon as the user presses it. The user must press hard enough to overcome the resistance threshold. The actuating wall then caves in quickly and suddenly, which guarantees that the fluid stored in the reservoir of the dispenser is put under pressure immediately. The fluid is then dispensed with good spraying quality.
An object of the invention is to define another dispenser of that type, i.e. which has a reservoir having a deformable wall, and in which the fluid stored in the reservoir is dispensed in accurately metered manner and with good spraying quality.
Document U.S. Pat. No. 4,795,063 describes a dispenser comprising a flexible reservoir made up of two sheets sealed together around their peripheries. The reservoir contains a pump constituted by a base forming a piston and by a body in which the piston formed by the base is slidably received. The base also forms an inlet valve while the body forms an outlet valve. The body also forms a sealing flange to which an opening formed by one of the sheets is sealed. The base and the body are urged apart by a return spring. By bringing the base towards the body against the force exerted by the spring, the volume of the pump chamber is reduced, and fluid is delivered through the outlet valve that constitutes the dispensing orifice. The outer end of the base can be likened to a pusher, and said outer end is situated on the inside of a deformable wall of the reservoir. The outer end of the base can therefore be moved by pressing on the deformable wall of the reservoir. The fluid delivered by the pump exits from the dispenser at the outlet valve which is situated in alignment with the movement of the outer end. It is thus necessary to be careful, when actuating that dispenser, not to close off the outlet orifice with a finger, particularly since the ideal position for the finger serving as the backing finger against the thrust exerted on the outer end is the position of the outlet valve. Therefore, the fingers must be positioned beside the outlet valve so that the fluid dispensed might come into contact with the fingers, which is not the desired effect. It is thus not at all easy to use such a dispenser. This is due to the facts that the dispensing orifice is formed by the outlet valve, and that the outlet valve is situated at or opposite the deformable portion of the reservoir.
An object of the present invention is to remedy the drawbacks of that prior art.
To this end, the present invention provides a fluid dispenser comprising: a reservoir serving to contain fluid and defining an actuating wall; and a dispensing orifice via which the fluid is dispensed each time the wall of the reservoir is actuated; the reservoir further containing a pump defining a pump chamber provided with an inlet valve for communicating with the reservoir and with an outlet valve, the pump including a pusher which is pushed in order reduce the volume of the pump chamber, said pusher being disposed below the actuating wall of the reservoir; a delivery duct connecting the outlet valve of the pump to the dispensing orifice, the dispenser being characterized in that the pusher of the pump is formed by a deformable wall of the pump chamber. It may be a xe2x80x9cdiaphragm pumpxe2x80x9d in which the volume of the pump chamber is varied by a diaphragm being elastically deformed. When the diaphragm is pressed, it is deformed, and as soon as the pressure is released, said diaphragm returns to its original position. The return force of the pump is thus provided directly by the diaphragm. In addition, by offsetting the dispensing orifice relative to the pump by means of the delivery duct, the pump becomes completely invisible because it is contained entirely within the reservoir. The user believes that the dispenser is of the conventional type (without a pump). The user perceives a certain amount of resistance to deformation, imparted by the deformable wall of the pump. By continuing to press the actuating wall, a dose of fluid is dispensed: its metering and its spraying quality are guaranteed by the pump. A principle of the present invention lies in integrating the pump entirely inside conventional packaging having a deformable reservoir wall. Integrating a pump into such packaging offers other further advantages: for example, the actuating wall of the reservoir does not need to have shape memory since it is returned to its initial state by the return force of the pump that tends to return the pusher back into the rest position. The actuating wall of the reservoir may thus have a shape that is constant in the rest position regardless of the state of filling of the reservoir. In addition, the pump inside the reservoir imparts some strength to it so that it is easier for the user to take hold of it.
In a practical embodiment, the pump is fitted to a support piece defining the dispensing orifice. Advantageously, the delivery duct is formed by the support piece.
According to another characteristic, the reservoir is fixed to the support piece.
In another embodiment, the reservoir is made up of two deformable sheets sealed together around their peripheries. This is an entirely conventional design for a dispenser serving as a free sample for advertising purposes. The term xe2x80x9cdeformable sheetxe2x80x9d should be understood as extending to film laminates and to thermoformed shells, or to a combination of both.
Advantageously, the support piece is provided with a fixing appendage to which the sheets of the reservoir are fixed, advantageously by sealing. Thus, the fixing appendage closes off the reservoir.
In a practical embodiment, the support piece forms a recess into which component members of the pump are inserted. Advantageously, the support piece defines a valve seat for the inlet valve of the pump. The support piece is thus an integral part of the pump, because said pump cannot operate without it.
The invention is described more fully below with reference to the accompanying drawings which give an embodiment of the invention by way of non-limiting example.